Imagine that the inauguration of President George W. Bush had sparked an explosive rise in African-American militia groups. Suppose thousands of heavily armed black men began gathering at training camps in wooded areas throughout the country, devising military tactics for "taking back their country" after what they believed was an electoral coup.

Do you think Bush and Vice President Dick Cheney would have reacted to a black militaristic buildup as coolly as President Obama has to the phenomenal growth of white militias?

Since Obama took office last year, the number of white militias has shot up from about 170 to more than 500, according to the Southern Poverty Law Center, which monitors extremist groups in the United States. Armed with enough firepower to take on a police department, some of these groups are honing their sniper skills using photographs of Obama for target practice.

They cling to the delusion that the nation's first black president is somehow a subversive working for Muslim extremists, and they aim to bring him down.

"If the people we saw running around armed to the teeth were black, I think their organizations would be destroyed in a matter of hours," Mark Potok, director of the Southern Poverty Law Center's Intelligence Project, told me. "If people saw on their TV screens photos of black militia members shooting at images of a white president, I don't think they would last."